class_docstr: One-hot encoding for polyphonic events.
code: def event_to_num_steps(self, event):
      if event.event_type == PolyphonicEvent.STEP_END:
          return 1
      else:
          return 0
  
file_path: magenta/magenta/models/polyphony_rnn/polyphony_encoder_decoder.py
imports: from __future__ import division
  from magenta.models.polyphony_rnn import polyphony_lib
  from magenta.models.polyphony_rnn.polyphony_lib import PolyphonicEvent
  from note_seq import encoder_decoder
label_desc: Use image node_id 5 for calling the PolyphonyOneHotEncoding obj's underlying member method code with example usage: obj.event_to_num_steps(event) and returns: int, int